Psychology is concerned with the minds of men. It has two major meanings. The sciences of human action are not primarily concerned with the physiological meaning, sometimes known as natural or experimental psychology. Whenever Mises refers to psychology in economic studies, he has in mind what some call "literary psychology" and which he has called "Thymology" in ''Theory and History'' and ''The Ultimate Foundation of Economic Science''. In this sense, psychology "is on the one hand an offshoot of introspection and on the other a precipitate of historical experience. It is what everybody learns from intercourse with his fellows. It is what a man knows about the way in which people value different conditions, about their wishes and desires and their plans to realize these wishes and desires. It is the knowledge of the social environment in which a man lives and acts."
It signifies the cognition of human ideas, emotions, volitions, motivations and value judgments which are an indispensable faculty of everyone. It is the specific understanding of the past which gives men an insight into the minds of other men. Psychology, like economics, starts with the individual. It concerns the internal invisible and intangible events of the mind which determine man's value scales which result or can result in action. Economics begins at the point psychology leaves off.
- Percy L. Greaves, Jr. "Mises Made Easier ", 1974. Referenced 2014-08-20.